Pumps, and in particular fuel injection pumps having opposed pistons and a rotary distributing valve element



Feb. 2, 1965 P. E. BESSIERE 3,168,042

} PUMPS, AND IN PARTICULAR FUEL. INJECTION PUMPS HAVING OPPOSED I PISTONS AND A ROTARY DISTRIBUTING VALVE ELEMENT Filed Dec. 27, 1960 5 Sheets-Sheet 1 I 211 5 J6 J5 m Kn x ATTORNEYS Feb. 1965 P. E. BESSIERE 3,168,042

PUMPS, AND IN PARTICULAR FUEL INJECTION PUMPS HAVING OPPOSED PISTONS AND A ROTARY DISTRIBUTING VALVE ELEMENT Filed Dec. 27, 1960 3 Sheets-Sheet 2 VEN r R 7/5 fi 21 m v ATmR vEYj 3 1965 P. E. BESSIERE 3 ,042

PUMPS, AND IN PARTICULAR FUEL INJECTION PUMPS HAVING OPPOSED PISTONS AND A ROTARY DISTRIBUTING VALVE ELEMENT Filed Dec. 27, 1960 3 Sheets-Sheet 3 INVENTUR #15826 swan/v6 flass M BY.

United States Patent @fihee sl'ihbfi iz Patented Feb. 2, 1955 3,163,042 PUMlS, AND EN kARTiQULAR lNJEtITiOh-i EUR ii HAVENG Sl kiiSED hisiTtiNd r 2) A RKBTARY DES'EREBUTLNG VALVE ELEh iifibh Pierre Etienne Eessiere, bleniily-sur-Seine, France, as= signer to Societe Anonyme pour lllrrploitation des Procedes Chirniques et Physiques, Zug, Switzerian a Swiss company Filed Dec. 2'7, 39%, Set. No. 78,472 iilairns priority, application France, 8, 1954), $15,223 Ciairns, (Cl. 1ll3--2} The present invention relates to self-regulating pumps, especially for the feed of fuel to internal combustion engines, of the type comprising a first part, which is fixed, and a second part rotating with respect to said first part and acting as a distributing valve element having an outlet adapted to come in communication, during the rotation of said second part, successively with a plurality of delivery means, one of these two parts carrying -a cam and the other a pair of opposed cylinders, with pistons slidable in said cylinders respectively and operatively connected with said cam to be reciprocated by it, this last mentioned part being provided with a delivery conduit adapted to connect said cylinders, during the delivery strokes of the pistons therein, with said distributing valve element outlet as it is in communication with one of said delivery means.

In prior patents and patent applications, I already described pumps of this kind wherein said regulation obtained by means of a movable member called shuttle which, during the delivery strokes of the pump piston, is driven, to effect its own outward stroke, by a liquid delivered by this piston or preferably by an auxiliary piston working in synchronism with the pump piston, and which, at the end of its outward stroke, opens a discharge conduit for the liquid which is driving said shuttle, so as to stop fuel injection to the internal combustion engine whereas the return stroke of the shuttle is produced, between two consecutive delivery strokes of the pump piston, by a spring, these return strokes being braked by the fact that the shuttle, during said return strokes, must force at least a portion of the liquid by which its outward stroke had been produced through a throttled passage which is preferably adjustable. Due to this braking of the return stroke of the shuttle and for speeds of rotation of the pump exceeding a given value (i.e. for speeds of the engine fed by the pump also exceeding a given value) the shuttle on its return stroke has not yet reached, when the next delivery of the pump begins, its position of rest, determined by an butment against which the above men tioned spring tends to apply it at the end of its return stroke. In this case, the shuttle is compelled to start back on its next outward stroke after an incomplete return stroke, which is the shorter as the speed increases beyond the above mentioned given value. This produces a corresponding reduction of the amount of fuel injected into the engine during every cycle of the The phenomenon thus produced to ensure regulation of the pump is called liquid abutment.

The object of the present invention is to provide a pump having opposed pistons and a rotary distributing valve element as above mentioned with regulating means based on said liquid abutment phenomenon.

For this purpose, according to my invention, the fixed part is provided with a cylindrical housing in which is slidably mounted a shuttle piston which during each of said delivery strokes is driven, on its outward strokes, by liquid delivered either by said pistons or, preferably, by auxiliary pistons movin in synchronisrn with said pistons, said shuttle, at the end of every outward stroke thereof, opening a discharge conduit for said liquid in such manner as then to stop the flow of fuel through said delivery conduit, the return strokes of said shuttle, which take place during the intervals between consecutive delivery strokes of the pump pistons, being produced by a spring, and being braked by the fact that the shuttle, during said return strokes, must force through a, throttle passage at least a portion of the liquid which had previously driven it on its outward stroke, whereby, for speeds of rotation of the pump above a given value, the outward strokes of the shuttle become shorter and shorter as this speed increases, and consequently fuel ilow through the delivery conduit is stopped after a shorter and shorter portion of the delivery strokes of the pump pistons.

Preferred embodiments of the present invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example and in which:

FIG. 1 is a diagrammatic axial sectional view of a pump made accordin to a first embodiment of the present invention, the parts being shown in the position corresponding to the end of a delivery stroke of the pistons.

FIGS. 2 and 3 are longitudinal sectional views of the pump of PEG. 1 respectively in the relative positions of the parts corresponding to fuel delivery and to suction.

FIGS. 4 and 5 are diagrammatic axial sectional views of two pumps made according to a second embodiment and a third embodiment respectively of the invention.

6 and 7 are cross-sections on the lines VlVl and Vii Vii respectively of MG. 1.

in the embodiment of F188. 1 and 3, the pump cornprises on the one hand a fixed part l which carries earn 2 of annular shape and on the other hand a rotating part 3 acting as a distributing valve ele'nent. Part 3 is provided with a recess 4, form ng two opposed cylinders, in which slidable opposed pistons 5. A pushpiece 25 provided with a roller 7 is interposed between 2 and each of the pistons 5. The working space E which is limited, in recess 4-, by the two pistons 5, is in "1511i communication with a conduit 9 extending ongitudinally rotating part 3. This conduit 9 serves both to suck in fuel from a feed chamber it) through channel 11 provided in fixed part 1 and radial channels 12 provided in rotating part 3 and to deliver fuel toward fuel injectors (not visible on the drawings) through connecting members such as 13 provided with check valves 14-, radial channels such as 15 provided in fixed part it and a radial channel provided in rotating part 3 which thus works as a distributing valve element. Chamber 1% is fed with fuel from a feed pump 17 driven by rotating part 3, this feed pump being preferably a gear L unrp shown.

Fixed part 1 i provided with a discharge conduit 1 .8 arranged to be in communication with delivery conduit 5? during the delivery strokes of opposed pistons 5, this discharge conduit being controlled by a shuttle member adapted to work according to the so-called liquid abutment phenomenon.

For this purpose, rotating part 3 is provided with radial channels Ztl, permanently in communication with delivery conduit 9 and adapted to connect said conduit with discharge conduit 18 every time delivery conduit 9 is in communication with one of the fuel injectors through channels 15 and 1:).

Shuttle is operated by the following means.

Every carries, inte l therewith an auxiliary piston 5a of larger diameter sliding in a corresponding cylinder formed in part 3 so as to form two variable volume working chambers El. These chambers 21 are connected to a common channel 22 which, during every delivery stroke of the main piston 53, is placed in com.- munication, through longitudinal groove provided in the periphery of rotary part 3 and a channel 24 provided in fixed part 1, with a variable volume chamber 25 limited by one of the end faces of shuttle 19 (FIG. 2). On the other hand, this channel 22, during every suction stroke of main piston 5, is placed in communication, through channel 26 provided in rotary part 3 and channel 27 provided in fixed part 1, with feed chamber 1t (FIG. 3). Thus, during every delivery stroke of main piston 5, shuttle 19 moves on its outward stroke (toward the right hand side of FIG. 2) under the action of the liquid delivered by auxiliary piston 50.. The end of this outward stroke of the shuttle is determined by the fact that this shuttle clears an outiet conduit 28, said shuttle then also clearing, through its groove 19a, discharge conduit 18. During the suction stroke of the main piston 5 (FIG. 3), shuttle 19 moves on its return stroke under the action of a return spring 29 but this movement is braked by the fact that the shuttle must force the liquid precedingly admitted into chamber 25 to flow through throttled passage 3% which is preferably adjustable by means of a screw 31. This is due to the fact that, during said return strokes of the shuttle, chamber 25 is on the one hand cut off from channel 22 due to the displacement of groove 23 and on the other hand placed in communication with a channel 32, which contains throttled passage 30, through a longitudinal groove 33 and an annular groove 34 provided in rotating part 3. (lensequently, when the speed of rotation of the pump is above a given value, shuttle 19 before reaching his position of rest which is determined by an abutment 35, is struck by a jet of fuel delivered by auxiliary pistons 50, which starts a new outward stroke of the shuttle. This outward stroke is therefore shortened, so that the time at which the shuttle clears discharge passage 18 occurs earlier during every cycle of the pump. Thus the amount of fuel delivered by main pistons 5 through delivery conduit 9 is reduced.

Annular earn 2 may be adjustable angularly with respect to fixed part 1 so as to vary the advance of injection. Furthermore the fiont edge of the groove 19a of shuttle 19 may be inclined, as shown at 1%, so that an angular adjustment of the shuttle, effected for instance by acting on a square portion 36 thereof, perm-its of varying the amount of fuel delivered on every cycle of the pump.

In the embodiments of FIGS. 4 and 5, cam 2 is carried by the rotating element 3 and the opposed pistons 5 are reciprocable in fixed part 1.

In the construction of FIG. 4, earn 2 is annular and the portion of rotating part 3 which acts as a distributing valve is of tubular shape. In this portion is engaged a cylindrical extension In of fixed part 1 through which extends delivery conduit 9. In FIG. 4, the same reference numerals have been used to designate elements having the same functions as the corresponding elements of FIGS. 1 to 3. These two embodiments (FIG. 4 and FIGS. 1-3) differ essentially by the fact that in the construction of FIG. 4 a spring 37 must be provided to urge piston 5 away from each other, whereas such a spring is not necessary in the construction of FIGS. 1-3, where the centrifugal force plays the same part as this spring. Furthermore in the construction of FIG. 4 where conduit 9 is provided in fixed part 1, this conduit is permanently in communication with the groove 19a of shuttle 19. Finally there must be provided, between chamber 25 and channel 22 which communicates with the two variable volume chambers 21 of auxiliary piston 5a, a check valve 38 which compels the liquid forced out by the shuttle to pass through throttled passage 3th Fixed part 1 may be adjusted angularly with respect to the pump frame 39 so as to vary the advance of injection.

According to the embodiment of FIG. 5, earn 2 is a solid rounded cam and pistons 5 are disposed on opposite sides of this cam so that it is necessary to provide two return springs 37a and 37b and two distinct working spaces 8a and 8b, which are connected together by channel 40 and a groove 41 of rotating part 3. This groove is in permanent communication with delivery conduit 9 which, as in the case of FIGS. 1 to 3, is pro vided in rotating part 3. The feed chamber analogous to those shown at 10 in FIGS. 1 and 4 is not visible in FIG. 5 and it is connected, through channels 11 and grooves 12a playing the same part as the channels 12 of FIGS. 1 to 4, with delivery conduit 9. Likewise, grooves 16a play the same part as the distribution channels 16 of FIGS. 1 to 4. The variable volume chambers 21 of auxiliary piston 5a are connected together by channels 4-2, longitudinal grooves 23a analogous to grooves 23 of FIGS. 1, 2, 3 and annular grooves 43 provided in rotating part 3, said grooves being in permanent communication, through channel 24, with the chamber 25 of the shuttle. Finally, longitudinal grooves 33a, communicating with said grooves 43, play a part analogous to that of the longitudinal groove 33 of FIGS. 1 to 3.

As the elements of the pump of FIGS. 4 and 5 are analogous to those of the pump of FIGS. 1 to 3 or perform analogous functions, it is unnecessary to describe the operation of the pump of FIGS. 4 and 5.

In a general manner, while I have, in the above de soription, disclose what I deem to be practical and ethcient embodiments of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form-of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

V-Jhat I claim is:

1. For use with aninternal combustion engine, a fuel feed pump which comprises, in combination, a first part provided with a recess forming two communicating pump cylinders opposed to each other, two pistons each reciprocable in one of said cylinders respectively, said two pistons limiting with said cylinders two variable volume spaces respectively, said two pistons limiting between them a Working space, a second part, said two parts being rotatable with respect to each other about an axis transverse to the axes of said cylinders, a cam carried by said second part, means for operatively connecting said pistons with said cam so that, under the elfect of the rotation of said two parts with respect to each other, said pistons are reciprocated in said cylinders respectively, with opposed movements, the movements of said pistons in the respective directions for which the volume of said working space is reduced being called delivery strokes and those in the respective opposed directions return strokes of said pistons, said cam comprising a number of lobes, each of said lobes being capable of producing, by cooperation with said pistons, a delivery stroke followed by a return stroke thereof, one of said parts being provided with a delivery conduit in constant communication with said working space, one of said parts being provided with a cylindrical housing arranged to communicate with said delivery conduit during the delivery strokes of said pistons and said housing having a discharge port, a reciprocating shuttle fitting slidably in said cylindrical housing adapted to clear said discharge port, so as to place it in communication with said delivery conduit, during the corresponding delivery strokes of said pistons, said shuttle being slidable in piston-like fashion in said housing so as to limit with the inner wall thereof a variable volume chamber, the movements of said shuttle in said housing in the direction for which the volume of said variable volume chamber is increased being called outward strokes and those in the opposed direction return strokes of said shuttle, a plurality of fuel delivery means carried by that of said parts which is not provided with said delivery conduit, the number of said delivery means being equal to the number of lobes of said cam, cooperating conduit means in said two parts arranged to connect each of said delivery means successively with said delivery conduit as one of said cam lobes is cooperating with said pistons to produce delivery strokes thereof, said parts being provided with repective passages arranged to communicate together and with said variable volume chamber during the return strokes of said pistons for form an outflow conduit having a throttled portion of cross-section very substan tially less than the cross-section of said shuttle, means operative by said pistons and comprising passages in said parts out of communication with said delivery conduit, for connecting said variable volume spaces to said variable volume chamber to feed liquid to said variable volume chamber during the delivery strokes of said pistons to produce outward strokes of said shuttle, and means operatively connected with said shuttle for urging said shuttle with a substantially constant force to produce the return strokes thereof, whereby, for speeds of rotation of said parts with respect to each other above a given value, said shuttle return strokes are the shorter as said speed of rotation is higher.

2. A pump according to claim 1, in which said second part is fixed and said first part is mounted to rotate with respect thereto, said cam surrounding said pistons.

3. A pump according to claim 1, in which said first part is fixed and said second part is mounted to rotate with respect thereto.

4. A pump according to claim 1 in which said first part is fixed and said second part is mounted to rotate with respect thereto, said cam surrounding said pistons.

5. A pump according to claim 1, in which said first part is fixed and said second part is mounted to rotate with respect thereto, said cam being of rounded shape and being interposed between said pistons.

References Cited by the Examiner UNITED STATES PATENTS 2,789,173 2/57 Herbrich 103154 2389,093 6/61 Evans l032.1 3,627,843 4/ 62 Raibaud 103-42 FOREIGN PATENTS 692,723 6/53 Great Britain.

JOSEPH H. BRANSON, ]R., Primary Examiner. 

1. FOR USE WITH AN INTERNAL COMBUSTION ENGINE, A FUEL FEED PUMP WHICH COMPRISES, IN COMBINATION, A FIRST PART PROVIDED WITH A RECESS FORMING TWO COMMUNICATING PUMP CYLINDERS OPPOSED TO EACH OTHER, TWO PISTONS EACH RECIPROCABLE IN ONE OF SAID CYLINDERS RESPECTIVELY, SAID TWO PISTONS LIMITING WITH SAID CYLINDERS TWO VARIABLE VOLUME SPACES RESPETIVELY, SAID TWO PISTONS LIMITING BETWEEN THEM A WORKING SPACE, A SECOND PART, SAID TWO PARTS BEING ROTATABLE WITH RESPECT TO EACH OTHER ABOUT AN AXIS TRANSVERSE TO THE AXES OF SAID CYLINDERS, A CAM CARRIED BY SAID SECOND PART, MEANS FOR OPERATIVELY CONNECTING SAID PISTONS WITH SAID CAM SO THAT, UNDER THE EFFECT OF THE ROTATIONS OF SAID TWO PARTS WITH RESPECT TO EACH OTHER, SAID PISTONS ARE RECIPROATED IN SAID CYLINDERS RESPECTIVELY, WITH OPPOSED MOVEMENTS, THE MOVEMENTS OF SAID PISTONS IN THE RESPECTIVE DIRECTIONS FOR WHICH THE VOLUME OF SAID WORKING SPACE IN REDUCED BEING CALLED DELIVERY STROKES AND THOSE IN THE RESPECTIVE OPPOSED DIRECTIONS RETURN STROKES OF SAID PISTONS, SAID CAM COMPRISING A NUMBER OF LOBES, EACH OF SAID LOBES BEING CAPABLE OF PRODUCING, BY COOPERATION WITH SAID PISTONS, A DELIVERY STROKE FOLLOWED BY A RETURN STORKE THEREOF, ONE OF SAID PARTS BEING PROVIDED WITH A DELIVERY CONDUIT IN CONSTANT COMMUNICATION WITH SAID WORKING SPACE, ONE OF SAID PARTS BEING PROVIDED WITH A CYLINDRICAL HOUSING ARRANGED TO COMMUNICATE WITH SAID DELIVERY CONDUIT DURING THE DELIVERY STROKES OF SAID PISTONS AND SAID HOUSING HAVING A DISCHARGE PORT, A RECIPROCATING SHUTTLE FITTING SLIDABLY IN SAID CYLINDRICAL HOUSING ADAPTED TO CLEAR SAID DELIVERY CONDUIT, DURING THE COMMUNICATION WITH SAID DELIVERY CONDUIT, DURING THE CORRESPONDING DELIVERY STROKES OF SAID PISTONS, SAID SHUTTLE BEING SLIDABLE IN PISTON-LIKE FASHION IN SAID HOUSING SO AS TO LIMIT WITH THE INNER WALL THEREOF A VARIABLE VOLUME CHAMBER, THE MOVEMENT OF SAID SHUTTLE IN SAID HOUSING IN THE DIRECTION FOR WHICH THE VOLUME OF SAID VARIABLE VOLUME CHAMBER IS INCREASED BEING CALLED OUTWARD STROKES AND THOSE IN THE OPPOSITE DIRECTION RETURN STROKES OF SAID SHUTTLE, A PLURALITY OF FUEL DELIVERY MEANS CARRIED BY THAT OF SAID PARTS WHICH IS NOT PROVIDED WITH SAID DELIVERY CONDUIT, THE NUMBER OF SAID DELIVERY MEANS BEING EQUAL TO THE NUMBER OF LOBES OF SAID CAM, COOPERATING CONDUIT MEANS IN SAID TWO PARTS ARRANGED TO CONNECT EACH OF SAID DELIVERY MEANS SUCCESSIVELY WITH SAID DELIVERY CONDUIT AS ONE OF SAID CAM LOBES IS COOPERATING WITH SAID PISTONS TO PRODUCE DELIVERY STROKES THEREOF, SAID PARTS BEING PROVIDED WITH RESPECTIVE PASSAGES ARRANGED TO COMMUNICATE TOGETHER AND WITH SAID VARIABLE VOLUME CHAMBER DURING THE RETURN STROKES OF SAID PISTONS FOR FORM AN OUTFLOW CONDUIT HAVING A THROTTLED PORTION OF CROSS-SECTION VERY SUBSTANTIALLY LESS THAN THE CROSS-SECTION OF SAID SHUTTLE, MEANS OPERATIVE BY SAID PISTONS AND COMPRISING PASSAGES IN SAID PARTS OUT OF COMMUNICATION WITH SAID DELIVERY CONDUIT, FOR CONNECTING SAID VARIABLE VOLUME SPACES TO SAID VARIABLE VOLUME CHAMBER TO FEED LIQUID TO SAID VARIABLE VOLUME CHAMBER DURING THE DELIVERY STROKES OF SAID PISTONS TO PRODUCE OUTWARD STROKES OF SAID SHUTTLE, AND MEANS OPERATIVELY CONNECTED WITH SAID SHUTTLE FOR URGING SAID SHUTTLE WITH A SUBSTANTIALLY CONSTANT FORCE TO PRODUCE THE RETURN STROKES THEREOF, WHEREBY, FOR SPEEDS OF ROTATION OF SAID PARTS WITH RESPECT TO EACH OTHER ABVE A GIVEN VALUE, SAID SHUTTLE RETRUN STROKES ARE THE SHORTER AS SAID SPEED OF ROTATION IS HIGHER. 